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Tool/software:
Hi team,
If I want to use OVP and UVP with the default values (OVP=32.6V, UVP=14.9V), is it correct to set R3=0Ω, R1=0Ω, and R2=open?
Should R2 have a set value?
Also, if I want to use OVP with the default settings and not use UVP (keeping it as low as possible), would it be acceptable to set R3=0Ω, R1=820kΩ (for example), and R2=open?
Should R2 have a set value?
Hello,
Welcome to E2E.
Yes, resistance values are fine for your configuration.
Thanks
Amrit
Hi, Amrit
Thank you for your reply.
I’m sorry.
I’m getting a bit confused.
Qusestion1)
If I short the OVP pin to RTN, can I understand that V(OV) will be set to the default V(OVPR) = 32.6V?
Is it right?
Qusestion2)
On the other hand, how can I use UVLO with the default V(UVP) = 14.9V?
Should I short the UVLO pin to VIN, or should I short UVLO to RTN?
Qusestion3)
Also, if I previously mentioned
R3 = 0Ω, R1 = 820kΩ (for example), and R2 = open,
but, then according to the relationships in (9) , V(OV) cannot be calculated because R3 is 0Ω.
When R3 is 0, do I need to consider it separately from the relationship in (9)?
Qusestion4)
If I am not using UVLO (when setting the value to near 0), what should I do?
Qusestion5)
Is it acceptable to leave R2 open?
Thanks
Hello,
Q1: Yes. The TPS26400 also feature a factory set 33-V Input overvoltage cut off V(IN_OVP) threshold with a 2-V hysteresis.
Q2: yes, Connect UVLO pin to RTN pin to select the internal default threshold
design calculator will show the values of R1,R2, R3 when you want to use adjustable UVLO or OVP.
If you are using default value, follow the above instruction.
Thanks
Amrit
Hi, Amrit
Thank you for your reply.
Q1, Q2 is OK.
NEW Q1)
When using UVLO or OVP with the default settings, I understand that R2 and R3 should be set to 0 and shorted to RTN.
In that case, do you have a recommended value for R1? Is it acceptable for R1 to be open?
NEW Q2)
If I want to use UVLO with a default value below 15V, what should I do?
I would like to set it to the smallest possible value.
In that case, is it okay to set R1 = 0, R3 = 0, and R2 = 820k (for example)?
Or should I set R1 = 0, R3 = 0, and R2 = open?
Thanks
Hello,
No need for R1,R2,R3
connect UVLO pin to RTN and OVP pin to RTN.
Thanks
Amrit
Hi, Amrit
Thank you for your reply.
>connect UVLO pin to RTN and OVP pin to RTN.
In this case, I understand that with the default settings (OVP = 32.6V, UVP = 14.9V).
However, I would like to use UVP below 15V. I want to set it to the smallest possible value.
n that case, is it okay to set R1 = 0, R3 = 0, and R2 = 820k (for example)?
Or should I set R1 = 0, R3 = 0, and R2 = open?
Thanks
Hello,
If you want to use value other than the default value, you have to use resistor divider to set the value.
To keep smallest as possible, then you can use
R1=820K, R2= open, R3=0
Thanks
Amrit